function trail = genTrail( suppData )
%UNTITLED2 Summary of this function goes here
%   Detailed explanation goes here
    nFrames = length(suppData);
    trail= [];
    for iFrame = 1: nFrames;
           sktp = suppData(iFrame).SktpAll;
             if ~isempty(sktp)
                 trailPoints = sktp(7,:);
                 trail = [trail;trailPoints];
            end
     end

end

